#!/usr/bin/env python

# print "*** EXPERIMENTAL PIANO VERSION WITH NOTE CACHING ***"

"""
##########################################################################
#                       * * *  PySynth  * * *
#       A very basic audio synthesizer in Python (www.python.org)
#
#          Martin C. Doege, 2009-06-08 (mdoege@compuserve.com)
##########################################################################
# Based on a program by Tyler Eaves (tyler at tylereaves.com) found at
#   http://mail.python.org/pipermail/python-list/2000-August/041308.html
##########################################################################

# 'song' is a Python list (or tuple) in which the song is defined,
#   the format is [['note', value]]

# Notes are 'a' through 'g' of course,
# optionally with '#' or 'b' appended for sharps or flats.
# Finally the octave number (defaults to octave 4 if not given).
# An asterisk at the end makes the note a little louder (useful for the beat).
# 'r' is a rest.

# Note value is a number:
# 1=Whole Note; 2=Half Note; 4=Quarter Note, etc.
# Dotted notes can be written in two ways:
# 1.33 = -2 = dotted half
# 2.66 = -4 = dotted quarter
# 5.33 = -8 = dotted eighth
"""

import wave
import struct
import numpy as np
from math import sin, cos, pi, log, exp
# from demosongs import *
from mkfreq import getfreq
pitchhz, keynum = getfreq()

# Harmonic intensities (dB) for selected piano keys,
# measured with output from a Yamaha P-85
harmo = (
    (1, -15.8, -3., -15.3, -22.8, -40.7),
    (16, -15.8, -3., -15.3, -22.8, -40.7),
    (28, -5.7, -4.4, -17.7, -16., -38.7),
    (40, -6.8, -17.2, -22.4, -16.8, -75.6),
    (52, -8.4, -19.7, -23.5, -21.6, -76.8),
    (64, -9.3, -20.8, -37.2, -36.3, -76.4),
    (76, -18., -64.5, -74.4, -77.3, -80.8),
    (88, -24.8, -53.8, -77.2, -80.8, -90.),
)


def linint(arr, x):
    "Interpolate an (X, Y) array linearly."
    for v in arr:
        if v[0] == x:
            return v[1]
    xvals = [v[0] for v in arr]
    ux = max(xvals)
    lx = min(xvals)
    try:
        assert lx <= x <= ux
    except:
        # print lx, x, ux
        raise
    for v in arr:
        if v[0] > x and v[0] - x <= ux - x:
            ux = v[0]
            uy = v[1]
        if v[0] < x and x - v[0] >= lx - x:
            lx = v[0]
            ly = v[1]
    # print lx, ly, ux, uy
    return (float(x) - lx) / (ux - lx) * (uy - ly) + ly


harmtab = np.zeros((88, 20))

for h in range(1, len(harmo[0])):
    dat = []
    for n in range(len(harmo)):
        dat.append((float(harmo[n][0]), harmo[n][h]))
    for h2 in range(88):
        harmtab[h2, h] = linint(dat, h2+1)

# print harmtab[keynum['c4'],:]
for h2 in range(88):
    for n in range(20):
        ref = harmtab[h2, 1]
        harmtab[h2, n] = 10.**((harmtab[h2, n] - ref)/20.)
# print harmtab[keynum['c4'],:]

##########################################################################
# Main program starts below
##########################################################################
# Some parameters:

# Beats (quarters) per minute
# e.g. bpm = 95

# Octave shift (neg. integer -> lower; pos. integer -> higher)
# e.g. transpose = 0

# Playing style (e.g., 0.8 = very legato and e.g., 0.3 = very staccato)
# e.g. leg_stac = 0.6

# Volume boost for asterisk notes (1. = no boost)
# e.g. boost = 1.2

# Output file name
#fn = 'pysynth_output.wav'

# Other parameters:

# Influences the decay of harmonics over frequency. Lowering the
# value eliminates even more harmonics at high frequencies.
# Suggested range: between 3. and 5., depending on the frequency response
#  of speakers/headphones used
harm_max = 5.
##########################################################################


def make_wav(song, bpm=120, transpose=0, leg_stac=.9, boost=1.1, repeat=0, fn="out.wav", silent=False):
    data = []
    note_cache = {}
    cache_this = {}

    f = wave.open(fn, 'w')

    f.setnchannels(1)
    f.setsampwidth(2)
    f.setframerate(44100)
    f.setcomptype('NONE', 'Not Compressed')

    bpmfac = 120./bpm

    def length(l):
        return 88200./l*bpmfac

    def waves2(hz, l):
        a = 44100./hz
        b = float(l)/44100.*hz
        return [a, round(b)]

    att_len = 3000
    att_bass = np.zeros(att_len)
    att_treb = np.zeros(att_len)
    for n in range(att_len):
        att_treb[n] = linint(((0, 0.), (100, .2), (300, .7), (400, .6),
                              (600, .25), (800, .9), (1000, 1.25), (2000, 1.15), (3000, 1.)), n)
        att_bass[n] = linint(((0, 0.), (100, .1), (300, .2), (400, .15),
                              (600, .1), (800, .9), (1000, 1.25), (2000, 1.15), (3000, 1.)), n)
    decay = np.zeros(1000)
    for n in range(900):
        decay[n] = exp(linint(((0, log(3)), (3, log(5)),
                               (5, log(1.)), (6, log(.8)), (9, log(.1))), n/100.))

    def render2(a, b, vol, pos, knum, note):
        l = waves2(a, b)
        q = int(l[0]*l[1])

        lf = log(a)
        t = (lf-3.) / (8.5-3.)
        volfac = 1. + .8 * t * cos(pi/5.3*(lf-3.))
        schweb = waves2(lf*100., b)[0]
        schweb_amp = .05 - (lf-5.) / 100.
        att_fac = min(knum / 87. * vol, 1.)
        raw_note = 12*44100
        snd_len = min(max(int(3.1*q), 44100), raw_note)
        fac = np.ones(snd_len)
        fac[:att_len] = att_fac * att_treb + (1.-att_fac) * att_bass

        if note not in list(note_cache.keys()):
            x2 = np.arange(raw_note)
            sina = 2. * pi * x2 / float(l[0])
            ov = np.exp(-x2/3./decay[int(lf*100)]/44100.)
            new = ((np.sin(sina)
                    + ov*harmtab[kn, 2]*np.sin(2. * sina)
                    + ov*harmtab[kn, 3]*np.sin(3. * sina)
                    + ov*harmtab[kn, 4]*np.sin(4. * sina)
                    + ov*harmtab[kn, 5]*np.sin(8. * sina)
                    ) * volfac)
            new *= np.exp(-x2/decay[int(lf*100)]/44100.)
            if cache_this[note] > 1:
                note_cache[note] = new.copy()
                # print "Caching", note
        else:
            new = note_cache[note].copy()
        dec_ind = int(leg_stac*q)
        new[dec_ind:] *= np.exp(-np.arange(raw_note-dec_ind)/3000.)
        # if snd_len > raw_note:
        #     print("Warning, note too long:", snd_len, raw_note)
        #     snd_len = raw_note
        # print(snd_len)
        snd_len = min(snd_len, raw_note)
        # print("snd_len=", snd_len)
        # print("len1=", len(data[pos:pos+snd_len]))
        # print("len2=", len(new[:snd_len]))
        right = (new[:snd_len] * fac * vol *
                 (1. + schweb_amp * np.sin(2. * pi * np.arange(snd_len)/schweb/32.)))
        # print("len right=", len(right))
        data[pos:pos+snd_len] += right

    ex_pos = 0.
    t_len = 0
    for y, x in song:
        if x < 0:
            t_len += length(-2.*x/3.)
        else:
            t_len += length(x)
        if y[-1] == '*':
            y = y[:-1]
        if not y[-1].isdigit():
            y += '4'
        cache_this[y] = cache_this.get(y, 0) + 1
    # print "Note frequencies in song:", cache_this
    data = np.zeros(int((repeat+1)*t_len + 441000))
    # print len(data)/44100., "s allocated"

    for rp in range(repeat+1):
        for nn, x in enumerate(song):
            if not nn % 4 and silent == False:
                print("[%u/%u]\t" % (nn+1, len(song)))
            if x[0] != 'r':
                if x[0][-1] == '*':
                    vol = boost
                    note = x[0][:-1]
                else:
                    vol = 1.
                    note = x[0]
                if not note[-1].isdigit():
                    note += '4'		# default to fourth octave
                a = pitchhz[note]
                kn = keynum[note]
                a = a * 2**transpose
                if x[1] < 0:
                    b = length(-2.*x[1]/3.)
                else:
                    b = length(x[1])

                render2(a, b, vol, int(ex_pos), kn, note)
                ex_pos = ex_pos + b

            if x[0] == 'r':
                b = length(x[1])
                ex_pos = ex_pos + b

    ##########################################################################
    # Write to output file (in WAV format)
    ##########################################################################
    if silent == False:
        print("Writing to file", fn)

    data = data / (data.max() * 2.)
    out_len = int(2. * 44100. + ex_pos+.5)
    data2 = np.zeros(out_len, np.short)
    data2[:] = 32000. * data[:out_len]
    f.writeframes(data2.tostring())
    f.close()
    print()
